package com.heima.gateway.filter;

import com.alibaba.fastjson.JSON;
import com.heima.gateway.util.AppJwtUtil;
import io.jsonwebtoken.Claims;
import lombok.extern.slf4j.Slf4j;
import org.apache.commons.lang3.StringUtils;
import org.springframework.cloud.gateway.filter.GatewayFilterChain;
import org.springframework.cloud.gateway.filter.GlobalFilter;
import org.springframework.core.annotation.Order;
import org.springframework.core.io.buffer.DataBuffer;
import org.springframework.http.HttpStatus;
import org.springframework.http.MediaType;
import org.springframework.http.server.reactive.ServerHttpRequest;
import org.springframework.http.server.reactive.ServerHttpResponse;
import org.springframework.stereotype.Component;
import org.springframework.web.server.ServerWebExchange;
import reactor.core.publisher.Flux;
import reactor.core.publisher.Mono;

import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;

/**
 * 认证过滤器
 */
@Component
@Slf4j
@Order(0) // 值越小越优先执行
public class AuthorizeFilter implements GlobalFilter {
    private static List<String> urlList = new ArrayList<>();

    // 初始化白名单 url路径
    static {
        urlList.add("/login/in");
        urlList.add("/v2/api-docs");
    }

    /**
     * 过滤方法
     *
     * @param exchange 请求响应上下文
     * @param chain    过滤器对象
     * @return
     */
    @Override
    public Mono<Void> filter(ServerWebExchange exchange, GatewayFilterChain chain) {
        //1. 获取请求路径
        ServerHttpRequest request = exchange.getRequest();
        ServerHttpResponse response = exchange.getResponse();
        //2. 判断请求路径是否属于白名单 如果属于白名单 直接放行
        String reqUrl = request.getURI().getPath();
        for (String url : urlList) {
            if (reqUrl.contains(url)) {
                return chain.filter(exchange);
            }
        }
        //3. 判断请求头中是否有token
        String token = request.getHeaders().getFirst("token");
        //3.1 没有token 返回登录服务
        if (StringUtils.isBlank(token)) {
            //如果不存在，向客户端返回错误提示信息
            return writeMessage(exchange, "未携带token");
        }
        try {
            //3.2 有token 解析token信息
            Claims claims = AppJwtUtil.getClaimsBody(token);
            int verifyToken = AppJwtUtil.verifyToken(claims);
            if (verifyToken < 1) {
                Object id = claims.get("id");
                //4.放行到微服务 把id放到请求头中
                request.mutate().header("userId", String.valueOf(id));
                return chain.filter(exchange);
            }
        } catch (Exception e) {
            log.error("token 校验失败 :{}", e);
            return writeMessage(exchange, "认证失败，请重新登录");
        }
//        response.setStatusCode(HttpStatus.UNAUTHORIZED);
//        return response.setComplete();
        return writeMessage(exchange, "解析token已失效");
    }

    /**
     * 返回错误提示信息
     *
     * @return
     */
    private Mono<Void> writeMessage(ServerWebExchange exchange, String message) {
        Map<String, Object> map = new HashMap<>();
        map.put("code", HttpStatus.UNAUTHORIZED.value());
        map.put("errorMessage", message);
        //获取响应对象
        ServerHttpResponse response = exchange.getResponse();
        //设置状态码
        response.setStatusCode(HttpStatus.UNAUTHORIZED);
        //response.setStatusCode(HttpStatus.OK);
        //设置返回类型
        response.getHeaders().setContentType(MediaType.APPLICATION_JSON);
        //设置返回数据
        DataBuffer buffer = response.bufferFactory().wrap(JSON.toJSONBytes(map));
        //响应数据回浏览器
        return response.writeWith(Flux.just(buffer));
    }
}

